Benjamin Weaver
2011-Sep-30 14:33 UTC
[Xen-users] question re xen bridging: how would I enable different names for xen bridge and dom0 ethernet interface?
I have a 2-node xen cluster set up on 2 identical Linux Squeeze boxes. An ifconfig on one of the boxes is shown below. The only bridge configuration on our system is this: (network-script ''network-bridge netdev=eth0'') eth0 shows up as a bridge. A ''brctl showmacs eth0'' indicates as much. I would expect this, given my network-script line given above. But eth0 also has an ip associated with it, from dom0. I would also expect this too: that eth0 is the logical ethernet interface to dom0, given the usual explanations for name substitutions (eth0-> peth0, veth0->eth0). A typical explanation is given on http://www.sparksupport.com/blog/xen-bridging As I understand it, xen packet flow can be understood from the 2nd diagram on the url I have given. I am pretty sure I understand the usual explanation for the name substitutions on dom0. I would like a separate name for my xen bridge. I would like to call it by, say, the default name often mentioned in xen networking pages like the one above. 3 Questions: 1. Is eth0 in my configuration, both the dom0 logical interface and the xen bridge? It would have to be, which I do not understand, since I don''t think a bridge can be an interface and vice versa. 2. what does the ''netdev'' parameter do? as opposed to a network-script line like this: (network-script ''network-bridge bridge=eth0'') 3. how would I configure the system so that the dom0 logical ethernet interface is named differently from the xen bridge? 3a. how, for example, would I name my bridge xenbr0? An ifconfig on my system shows the following: eth1 (connected to a local SAN box), lo peth0 vif144.0 vif145.0. (this is a vm that we are continually migrating between the nodes in a stress test). sudo ifconfig eth0 Link encap:Ethernet HWaddr 00:15:17:80:3f:c6 inet addr:163.1.87.47 Bcast:163.1.87.255 Mask:255.255.254.0 inet6 addr: fe80::215:17ff:fe80:3fc6/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:111509205 errors:0 dropped:0 overruns:0 frame:0 TX packets:34583064 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:112192535136 (104.4 GiB) TX bytes:130624185882 (121.6 GiB) eth1 Link encap:Ethernet HWaddr 00:15:17:80:3f:c7 inet addr:192.168.0.41 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::215:17ff:fe80:3fc7/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:3468487649 errors:0 dropped:0 overruns:0 frame:0 TX packets:6724806778 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:491142175857 (457.4 GiB) TX bytes:9728780721480 (8.8 TiB) Memory:fc3a0000-fc3c0000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:90 errors:0 dropped:0 overruns:0 frame:0 TX packets:90 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:6144 (6.0 KiB) TX bytes:6144 (6.0 KiB) peth0 Link encap:Ethernet HWaddr 00:15:17:80:3f:c6 inet6 addr: fe80::215:17ff:fe80:3fc6/64 Scope:Link UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:6770049434 errors:0 dropped:1942 overruns:0 frame:0 TX packets:6670969718 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:6995794894068 (6.3 TiB) TX bytes:6737528247671 (6.1 TiB) Memory:fc3e0000-fc400000 vif144.0 Link encap:Ethernet HWaddr fe:ff:ff:ff:ff:ff inet6 addr: fe80::fcff:ffff:feff:ffff/64 Scope:Link UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:34510490 errors:0 dropped:0 overruns:0 frame:0 TX packets:66435470 errors:0 dropped:343 overruns:0 carrier:0 collisions:0 txqueuelen:32 RX bytes:1998543142 (1.8 GiB) TX bytes:100382092280 (93.4 GiB) vif145.0 Link encap:Ethernet HWaddr fe:ff:ff:ff:ff:ff inet6 addr: fe80::fcff:ffff:feff:ffff/64 Scope:Link UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:34 overruns:0 carrier:0 collisions:0 txqueuelen:32 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Simon Hobson
2011-Sep-30 15:59 UTC
Re: [Xen-users] question re xen bridging: how would I enable different names for xen bridge and dom0 ethernet interface?
Benjamin Weaver wrote:>I have a 2-node xen cluster set up on 2 identical Linux Squeeze >boxes. An ifconfig on one of the boxes is shown below. > >The only bridge configuration on our system is this: > >(network-script ''network-bridge netdev=eth0'') > >eth0 shows up as a bridge. A ''brctl showmacs eth0'' indicates as >much. I would expect this, given my network-script line given above.OK, look back (not too far) in the archives and you''ll find plenty of advice to forget the Xen scripts (which I believe are being deprecated) and do it in the OS. Debian has good tools for setting up bridges, and all it takes is this in /etc/network/interfaces : auto ethext iface ethext inet static bridge_ports pethext address a.b.c.d netmask 255.255.255.0 You can rename your interfaces by editing /etc/udev/rules.d/70-persistent-net-rules Note that the interfaces file does *not* have an entry for pethext.>1. Is eth0 in my configuration, both the dom0 logical interface and >the xen bridge? It would have to be, which I do not understand, >since I don''t think a bridge can be an interface and vice versa.Yes. What you are missing is that you can treat a bridge as an interface, give it an IP address, and shunt packets through it. This is the normal way to set one up.>3. how would I configure the system so that the dom0 logical >ethernet interface is named differently from the xen bridge? >3a. how, for example, would I name my bridge xenbr0?See above - I have a bridge called ethext, and a physical interface called pethext. These can be anything you want (within reason). -- Simon Hobson Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed author Gladys Hobson. Novels - poetry - short stories - ideal as Christmas stocking fillers. Some available as e-books. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Benjamin Weaver
2011-Oct-03 13:31 UTC
Re: [Xen-users] question re xen bridging: how would I enable different names for xen bridge and dom0 ethernet interface?
Thanks, Simon, I will try this solution out when our stress test is done. Ben _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Simon Hobson
2011-Oct-03 13:53 UTC
Re: [Xen-users] question re xen bridging: how would I enable different names for xen bridge and dom0 ethernet interface?
BTW - I forgot to mention that you''ll also need to disable all the Xen network scripts. Make sure all instances of "network-script" are commented out. -- Simon Hobson Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed author Gladys Hobson. Novels - poetry - short stories - ideal as Christmas stocking fillers. Some available as e-books. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users